With blue-violet semiconductor lasers composed of a compound semiconductor, for example, InxAlyGa1-x-yN (0≦x, 0≦y, 0≦x+y≦1), in the past, a method in which the aluminum content of a clad layer is increased has been studied in an effort to sufficiently increase the confinement coefficient of light in the vertical direction at the active layer. However, if the aluminum content is raised, lattice mismatching with the substrate and other compound semiconductor layers results in internal strain in the aluminum-containing layer, which leads to cracking and other such problems.
To deal with this, a semiconductor laser element has been proposed in which a transparent electrode or a metal layer that functions as a clad layer and a current blocking layer having a stripe-like groove are disposed over the active layer, which shortens the time it takes to grow the compound semiconductor layer, makes the compound semiconductor layer into a thin film, and reduces cracking within the aluminum-containing layer (for example, Japanese Laid-Open Patent Application Publication Nos. 2006-41491-A and 2007-129236-A).